Greetings, The National Marine Fisheries Service (NOAA Fisheries) is announcing the finalization and availability of the “2024 Update to: Technical Guidance for Assessing the Effects of Anthropogenic Sound on Marine Mammal Hearing (Version 3.0): Underwater and In-Air Criteria for Onset of Auditory Injury and Temporary Threshold Shifts.” NOAA Fisheries has developed the 2024 Updated Technical Guidance for assessing the effects of anthropogenic sound on marine mammal species, underwater and in-air,under NOAA Fisheries’s jurisdiction. This document provides updated received level thresholds and auditory weighting functions, or acoustic criteria, based on the best available science, at which individual marine mammals are predicted to experience changes in their hearing sensitivity (either auditory injury or temporary threshold shift) for all anthropogenic sound sources. The 2024 Updated Technical Guidance is intended to be used by NOAA Fisheries analysts and managers and other relevant user groups, including other federal agencies, when seeking to determine whether and how their activities are expected to result in particular types of impacts to marine mammals via acoustic exposure. The 2024 Updated Technical Guidance replaces our previous 2018 Revised Technical Guidance. Electronic copies of the document containing the revised section of the 2024 updated acoustic guidance can be found at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mamm... Thank you for your interest in this document and for those who provided recent public comment. For more information, please contact Amy Scholik-Schlomer (amy.scholik@noaa.gov or 301-427-8449). Amy R. Scholik-Schlomer, Ph.D*. *(she/her/hers) Fishery Biologist (HQ Protected Resources Acoustic Coordinator) *NOAA's National Marine Fisheries Service* *Office of Protected Resources* *Permits and Conservation Division1315 East-West Hwy.Silver Spring, MD 20910* (301) 427-8449 Email: *Amy.Scholik@noaa.gov <Amy.Scholik@noaa.gov>* https://www.fisheries.noaa.gov/insight/understanding-sound-ocean